Exploring the Combined Action of Adding Pertuzumab to Branded Trastuzumab versus Trastuzumab Biosimilars for Treating HER2+ Breast Cancer.

The binding activity of various trastuzumab biosimilars versus the branded trastuzumab towards the glycosylated extracellular domain of the human epidermal growth factor receptor 2 (HER2) target in the presence of pertuzumab was investigated. We employed size exclusion chromatography with tetra-detection methodology to simultaneously determine absolute molecular weight, concentration, molecular size, and intrinsic viscosity. All trastuzumab molecules in solution exhibit analogous behavior in their binary action towards HER2 regardless of the order of addition of trastuzumab/pertuzumab. This analogous behavior of all trastuzumab molecules, including biosimilars, highlights the robustness and consistency of their binding activity towards HER2. Furthermore, the addition of HER2 to a mixture of trastuzumab and pertuzumab leads to increased formation of high-order HER2 complexes, up to concentrations of one order of magnitude higher than in the case of sequential addition. The observed increase suggests a potential synergistic effect between these antibodies, which could enhance their therapeutic efficacy in HER2-positive cancers. These findings underscore the importance of understanding the complex interplay between therapeutic antibodies and their target antigens, providing valuable insights for the development of more effective treatment strategies.

Phase Ia/b Study of Giredestrant ± Palbociclib and ± Luteinizing Hormone-Releasing Hormone Agonists in Estrogen Receptor-Positive, HER2-Negative, Locally Advanced/Metastatic Breast Cancer.

PURPOSE: Giredestrant is an investigational next-generation, oral, selective estrogen receptor antagonist and degrader for the treatment of estrogen receptor-positive (ER+) breast cancer. We present the primary analysis results of the phase Ia/b GO39932 study (NCT03332797). PATIENTS AND METHODS: Patients with ER+, HER2-negative locally advanced/metastatic breast cancer previously treated with endocrine therapy received single-agent giredestrant (10, 30, 90, or 250 mg), or giredestrant (100 mg) ± palbociclib 125 mg ± luteinizing hormone-releasing hormone (LHRH) agonist. Detailed cardiovascular assessment was conducted with giredestrant 100 mg. Endpoints included safety (primary), pharmacokinetics, pharmacodynamics, and efficacy. RESULTS: As of January 28, 2021, with 175 patients enrolled, no dose-limiting toxicity was observed, and the MTD was not reached. Adverse events (AE) related to giredestrant occurred in 64.9% and 59.4% of patients in the single-agent ± LHRH agonist and giredestrant + palbociclib ± LHRH agonist cohorts, respectively (giredestrant-only-related grade 3/4 AEs were reported in 4.5% of patients across the single-agent cohorts and 3.1% of those with giredestrant + palbociclib). Dose-dependent asymptomatic bradycardia was observed, but no clinically significant changes in cardiac-related outcomes: heart rate, blood pressure, or exercise duration. Clinical benefit was observed in all cohorts (48.6% of patients in the single-agent cohort and 81.3% in the giredestrant + palbociclib ± LHRH agonist cohort), with no clear dose relationship, including in patients with ESR1-mutated tumors. CONCLUSIONS: Giredestrant was well tolerated and clinically active in patients who progressed on prior endocrine therapy. Results warrant further evaluation of giredestrant in randomized trials in early- and late-stage ER+ breast cancer.

Treatment Exposure and Discontinuation in the PALbociclib CoLlaborative Adjuvant Study of Palbociclib With Adjuvant Endocrine Therapy for Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative Early Breast Cancer (PALLAS/AFT-05/ABCSG-42/BIG-14-03).

PURPOSE: The PALLAS study investigated whether the addition of palbociclib, an oral CDK4/6 inhibitor, to adjuvant endocrine therapy (ET) improves invasive disease-free survival (iDFS) in early hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer. In this analysis, we evaluated palbociclib exposure and discontinuation in PALLAS. METHODS: Patients with stage II-III HR+, HER2- disease were randomly assigned to 2 years of palbociclib with adjuvant ET versus ET alone. The primary objective was to compare iDFS between arms. Continuous monitoring of toxicity, dose modifications, and early discontinuation was performed. Association of baseline covariates with time to palbociclib reduction and discontinuation was analyzed with multivariable competing risk models. Landmark and inverse probability weighted per-protocol analyses were performed to assess the impact of drug persistence and exposure on iDFS. RESULTS: Of the 5,743 patient analysis population (2,840 initiating palbociclib), 1,199 (42.2%) stopped palbociclib before 2 years, the majority (772, 27.2%) for adverse effects, most commonly neutropenia and fatigue. Discontinuation of ET did not differ between arms. Discontinuations for non-protocol-defined reasons were greater in the first 3 months of palbociclib, and in the first calendar year of accrual, and declined over time. No significant relationship was seen between longer palbociclib duration or ≥ 70% exposure intensity and improved iDFS. In the weighted per-protocol analysis, no improvement in iDFS was observed in patients receiving palbociclib versus not (hazard ratio 0.89; 95% CI, 0.72 to 1.11). CONCLUSION: Despite observed rates of discontinuation in PALLAS, analyses suggest that the lack of significant iDFS difference between arms was not directly related to inadequate palbociclib exposure. However, the discontinuation rate illustrates the challenge of introducing novel adjuvant treatments, and the need for interventions to improve persistence with oral cancer therapies.

The Leptin Axis and Its Association With the Adaptive Immune System in Breast Cancer.

Adipose tissue secretes various peptides, including leptin. This hormone acts through the leptin receptor (Ob-R), which is expressed ubiquitously on the surface of various cells, including breast cancer cells and immune cells. Increasing evidence points to an interaction between the tumor microenvironment, tumor cells, and the immune system. Leptin plays an important role in breast cancer tumorigenesis and may be implicated in activation of the immune system. While breast cancer cannot be considered an immunogenic cancer, the triple-negative subtype is an exception. Specific immune cells - tumor infiltrating lymphocytes - are involved in the immune response and act as predictive and prognostic factors in certain breast cancer subtypes. The aim of this article is to review the interaction between adipose tissue, through the expression of leptin and its receptor, and the adaptive immune system in breast cancer.

Obesity and Breast Cancer: A Paradoxical and Controversial Relationship Influenced by Menopausal Status.

Breast cancer is the most common tumor in women worldwide, and an increasing public health concern. Knowledge of both protective and negative risk factors is essential for a better understanding of this heterogenous disease. We undertook a review of the recent literature and evaluated the relationship between obesity mediators and breast cancer development depending on menopausal status. Excess weight is now pandemic and has replaced tobacco as the main lifestyle-related risk factor for premature death. Although the prevalence of obesity/overweight has increased globally over the last 50 years, the potential harm attributable to excess fat has generally been underestimated. The relationship between overweight/obesity, breast cancer and overall risk appears to be highly dependent on menopausal status. Thus, obesity increases the risk of breast cancer in postmenopausal women but, conversely, it appears to be protective in premenopausal women. We evaluate the role of different clinical factors potentially involved in this seemingly contradictory relationship, including estrogen, mammogram density, adipokines, insulin-signaling pathway activation, and inflammatory status. A key focus of this review is to better understand the impact of body mass index and menopausal status on these clinical factors and, hence, provide some clarity into the inter-relationships involved in this controversial issue.

Predictive Role of Leptin Receptor (Ob-R) Overexpression in Patients with Early Breast Cancer Receiving Neoadjuvant Systemic Treatment.

The primary aim of this retrospective study was to investigate the correlation between the immunohistochemical expression of Ob-R (leptin receptor) with pCR (pathological complete response) in early breast cancer patients receiving neoadjuvant systemic treatment (NST). A total of 100 women with breast cancer receiving NST (2017-2020) followed by surgical resection were retrospectively obtained. Demographic parameters and clinicopathological factors (e.g., treatment modalities, immunohistochemistry (IHC), and cancer subtype) were obtained from the patient's clinical records. In the analyzed breast cancer cohort, high expression of Ob-R was found in 52% of tumors and there was a significantly higher incidence in the HER2+ and TNBC subgroups. Overall, a significantly greater percentage of patients with Ob-R positive tumors achieved pCR compared with Ob-R negative patients (57.7% vs. 27.1%; p = 0.002). This result was observed in most breast cancer subtypes. In patients with HER2+ breast cancer, there was no difference in Ob-R expression in relation to the HR status. Ob-R cell positivity was significantly higher in younger breast cancer patients (p = 0.008), those who were premenopausal (p = 0.011), and in those with a BMI > 25 kg/m2 (p = 0.019). A significantly greater percentage of early breast cancer patients with Ob-R positive tumors achieved pCR compared with Ob-R negative patients. Furthermore, breast cancer patients with positive Ob-R expression were significantly younger than those with negative Ob-R expression. This association was not explained by differences in BMI between young and old patients.

A Randomized Placebo Controlled Phase II Trial Evaluating Exemestane with or without Enzalutamide in Patients with Hormone Receptor-Positive Breast Cancer.

PURPOSE: To determine whether the androgen receptor (AR) inhibitor, enzalutamide, improves effectiveness of endocrine therapy (ET) in hormone receptor-positive (HR+) breast cancer. PATIENTS AND METHODS: In this phase II trial, patients with HR+/HER2 normal advanced/metastatic breast cancer were randomized 1:1 to exemestane 25 mg with placebo or exemestane 50 mg with enzalutamide 160 mg daily (NCT02007512). Two parallel cohorts enrolled patients with 0 (cohort 1) or 1 (cohort 2) prior ET for advanced disease. Progression-free survival (PFS) was the primary endpoint in the intent-to-treat (ITT) population of each cohort. Biomarkers were evaluated in an exploratory analysis. RESULTS: Overall, 247 patients were randomized (cohort 1, n = 127 and cohort 2, n = 120). PFS was not improved in either cohort of the ITT population [HR, 0.82 (95% confidence interval (CI), 0.54-1.26); P = 0.3631 for cohort 1 and HR, 1.02 (95% CI, 0.66-1.59); P = 0.9212 for cohort 2]. In cohort 1, high levels of AR mRNA were associated with greater benefit of enzalutamide (P interaction = 0.0048). This effect was particularly apparent in patients with both high levels of AR mRNA and low levels of ESR1 mRNA [HR, 0.24 (95% CI, 0.10-0.60); P = 0.0011]. The most common any grade adverse events in the enzalutamide arms were nausea (39%) in cohort 1 and fatigue (37%) in cohort 2. CONCLUSIONS: Enzalutamide with exemestane was well tolerated. While PFS was not improved by the addition of enzalutamide to exemestane in an unselected population, ET-naïve patients with high AR mRNA levels, particularly in combination with low ESR1 mRNA levels, may benefit from enzalutamide with exemestane.

Enhancing global access to cancer medicines.

Globally, cancer is the second leading cause of death, with numbers greatly exceeding those for human immunodeficiency virus/acquired immunodeficiency syndrome, tuberculosis, and malaria combined. Limited access to timely diagnosis, to affordable, effective treatment, and to high-quality care are just some of the factors that lead to disparities in cancer survival between countries and within countries. In this article, the authors consider various factors that prevent access to cancer medicines (particularly access to essential cancer medicines). Even if an essential cancer medicine is included on a national medicines list, cost might preclude its use, it might be prescribed or used inappropriately, weak infrastructure might prevent it being accessed by those who could benefit, or quality might not be guaranteed. Potential strategies to address the access problems are discussed, including universal health coverage for essential cancer medicines, fairer methods for pricing cancer medicines, reducing development costs, optimizing regulation, and improving reliability in the global supply chain. Optimizing schedules for cancer therapy could reduce not only costs, but also adverse events, and improve access. More and better biomarkers are required to target patients who are most likely to benefit from cancer medicines. The optimum use of cancer medicines depends on the effective delivery of several services allied to oncology (including laboratory, imaging, surgery, and radiotherapy). Investment is necessary in all aspects of cancer care, from these supportive services to technologies, and the training of health care workers and other staff.

Contextualizing pertuzumab approval in the treatment of HER2-positive breast cancer patients.

The use of adjuvant pertuzumab in HER2-positive early-stage breast cancer has recently been approved by the EMA on the basis of data from the APHINITY trial. Accordingly, we have produced this opinion article with the aim of putting the study data in perspective against other add-on therapeutic strategies, to clarify methodological or statistical doubts about the study, and to define the population of high-risk patients with hormone receptor-negative breast cancer that we agree, in general, should be treated. With this approval, physicians must be well prepared to place the APHINITY study data in context. It is now up to each country to ratify the EMA-approved indications and to agree on reimbursement, and doctors must optimize their use based on knowledge and discussion with patients.

Updating the role of obesity and cholesterol in breast cancer.

BACKGROUND: Breast cancer is the second most common cause of cancer-related death among women. Advances in our understanding of the disease have translated into better diagnostics and more effective therapeutics, leading to earlier detection and improved outcomes. Several studies have pointed at lifestyle and environmental factors as contributory for the onset and progression of the disease. Obesity and cholesterol stand out for their potential causal relationship with breast cancer and ease of modification. MAIN TEXT: Obesity and cholesterol represent risk factors for breast cancer, but their impact is largely affected by cofounding variables including menopausal status, disease subtype, and inflammation. Establishing a causal relationship between lifestyle factors and clinical outcomes may be challenging. Epidemiological studies and meta-analyses have rendered conflicting or sometimes contradictory results, possibly owing to the multifactorial nature of the disease. We discuss the supporting evidence and limitations in our understanding of obesity and cholesterol as risk factors for breast cancer. CONCLUSIONS: There is sufficient evidence that obesity and cholesterol impact clinical outcomes. Physicians are advised to take steps to help patients with their weight, such as recommending dietary and lifestyle interventions.

Randomized phase II study evaluating weekly oral vinorelbine versus weekly paclitaxel in estrogen receptor-positive, HER2-negative patients with advanced breast cancer (NorBreast-231 trial).

BACKGROUND: Single-agent paclitaxel and vinorelbine are recommended treatments for advanced breast cancer (ABC) non-responsive to hormone therapy and without visceral crisis. This phase II trial compared first-line oral vinorelbine versus weekly paclitaxel for ABC. METHODS: Eligible female patients had measurable locally recurrent/metastatic estrogen receptor-positive HER2-negative breast cancer and had received prior endocrine therapy (any setting) but no chemotherapy for ABC. Patients were stratified by prior taxane and visceral metastases and randomized to either oral vinorelbine 80 mg/m2 (first cycle at 60 mg/m2, escalated to 80 mg/m2 in the absence of grade 3/4 toxicity) or intravenous paclitaxel 80 mg/m2 on days 1, 8, and 15 every 3 weeks until disease progression or unacceptable toxicity. The primary endpoint was disease control rate (DCR; confirmed complete or partial response, or stable disease for ≥6 weeks). RESULTS: The 131 randomized patients had received a median of 2 prior endocrine therapies; >70% had prior (neo)adjuvant chemotherapy and 79% visceral metastases. DCR was 75.8% (95% confidence interval: 63.6-85.5%) with vinorelbine and 75.4% (63.1-85.2%) with paclitaxel. The most common grade 3/4 adverse events were neutropenia (52%), fatigue (11%), and vomiting (5%) with vinorelbine, and neutropenia (17%), dyspnea (6%), hypertension (6%), and peripheral sensory neuropathy (5%) with paclitaxel. Grade 2 alopecia occurred in 2% of vinorelbine-treated and 34% of paclitaxel-treated patients. Neither arm showed relevant global health status changes. CONCLUSION: Oral vinorelbine and paclitaxel demonstrated similar DCRs (∼75%). Safety profiles differed and, together with administration route and convenience, may influence treatment choice (EudraCT number, 2012-003530-16).

Experience with eribulin in patients with metastatic breast cancer and associated hepatic impairment: case studies.

Hepatic impairment in breast cancer arises from metastatic spread of tumor cells to the liver and signals a poor prognosis. Systemic therapy is the mainstay of treatment. Three women with hepatic dysfunction secondary to breast cancer who were treated with eribulin are presented herein. In the first case, third-line eribulin at the time of acute liver failure due to metastases maintained response for up to 9 months with good tolerability. In the second case, a woman with secondary bone and liver disease had progression-free survival of 5 months to third-line eribulin and, upon rechallenge after a drug holiday, had almost four more months of stable disease. Last, a heavily pretreated patient with secondary bone and hepatic involvement showed a response to fourth-line eribulin.

Enzalutamide for the Treatment of Androgen Receptor-Expressing Triple-Negative Breast Cancer.

Purpose Studies suggest that a subset of patients with triple-negative breast cancer (TNBC) have tumors that express the androgen receptor (AR) and may benefit from an AR inhibitor. This phase II study evaluated the antitumor activity and safety of enzalutamide in patients with locally advanced or metastatic AR-positive TNBC. Patients and Methods Tumors were tested for AR with an immunohistochemistry assay optimized for breast cancer; nuclear AR staining > 0% was considered positive. Patients received enzalutamide 160 mg once per day until disease progression. The primary end point was clinical benefit rate (CBR) at 16 weeks. Secondary end points included CBR at 24 weeks, progression-free survival, and safety. End points were analyzed in all enrolled patients (the intent-to-treat [ITT] population) and in patients with one or more postbaseline assessment whose tumor expressed ≥ 10% nuclear AR (the evaluable subgroup). Results Of 118 patients enrolled, 78 were evaluable. CBR at 16 weeks was 25% (95% CI, 17% to 33%) in the ITT population and 33% (95% CI, 23% to 45%) in the evaluable subgroup. Median progression-free survival was 2.9 months (95% CI, 1.9 to 3.7 months) in the ITT population and 3.3 months (95% CI, 1.9 to 4.1 months) in the evaluable subgroup. Median overall survival was 12.7 months (95% CI, 8.5 months to not yet reached) in the ITT population and 17.6 months (95% CI, 11.6 months to not yet reached) in the evaluable subgroup. Fatigue was the only treatment-related grade 3 or higher adverse event with an incidence of > 2%. Conclusion Enzalutamide demonstrated clinical activity and was well tolerated in patients with advanced AR-positive TNBC. Adverse events related to enzalutamide were consistent with its known safety profile. This study supports additional development of enzalutamide in advanced TNBC.

Selecting postoperative adjuvant systemic therapy for early stage breast cancer: A critical assessment of commercially available gene expression assays.

Risk stratification of patients with early stage breast cancer may support adjuvant chemotherapy decision-making. This review details the development and validation of six multi-gene classifiers, each of which claims to provide useful prognostic and possibly predictive information for early stage breast cancer patients. A careful assessment is presented of each test's analytical validity, clinical validity, and clinical utility, as well as the quality of evidence supporting its use.

Whole-exome sequencing reveals defective CYP3A4 variants predictive of paclitaxel dose-limiting neuropathy.

PURPOSE: Paclitaxel, a widely used chemotherapeutic drug, can cause peripheral neuropathies leading to dose reductions and treatment suspensions and decreasing the quality of life of patients. It has been suggested that genetic variants altering paclitaxel pharmacokinetics increase neuropathy risk, but the major causes of interindividual differences in susceptibility to paclitaxel toxicity remain unexplained. We carried out a whole-exome sequencing (WES) study to identify genetic susceptibility variants associated with paclitaxel neuropathy. EXPERIMENTAL DESIGN: Blood samples from 8 patients with severe paclitaxel-induced peripheral neuropathy were selected for WES. An independent cohort of 228 cancer patients with complete paclitaxel neuropathy data was used for variant screening by DHPLC and association analysis. HEK293 cells were used for heterologous expression and characterization of two novel CYP3A4 enzymes. RESULTS: WES revealed 2 patients with rare CYP3A4 variants, a premature stop codon (CYP3A4*20 allele) and a novel missense variant (CYP3A4*25, p.P389S) causing reduced enzyme expression. Screening for CYP3A4 variants in the independent cohort revealed three additional CYP3A4*20 carriers, and two patients with missense variants exhibiting diminished enzyme activity (CYP3A4*8 and the novel CYP3A4*27 allele, p.L475V). Relative to CYP3A4 wild-type patients, those carrying CYP3A4 defective variants had more severe neuropathy (2- and 1.3-fold higher risk of neuropathy for loss-of-function and missense variants, respectively, P = 0.045) and higher probability of neuropathy-induced paclitaxel treatment modifications (7- and 3-fold higher risk for loss-of-function and missense variants, respectively, P = 5.9 × 10(-5)). CONCLUSION: This is the first description of a genetic marker associated with paclitaxel treatment modifications caused by neuropathy. CYP3A4 defective variants may provide a basis for paclitaxel treatment individualization.

Treatment innovations for metastatic breast cancer: nanoparticle albumin-bound (NAB) technology targeted to tumors.

In spite of recent advances in the treatment of metastatic breast cancer, this disease remains essentially incurable. Anthracyclines and taxanes have been widely demonstrated to be the most active cytotoxic drugs for the treatment of breast cancer. Paclitaxel and docetaxel are both hydrophobic drugs that need to be administered with detergent-like substances as solvents. In contrast, nanoparticle albumin-bound (nab) paclitaxel uses the natural characteristics of albumin to reversibly bind paclitaxel, transport it across endothelial cells and concentrate the active ingredient within the tumor. Several trials have demonstrated that nab-paclitaxel results in superior efficacy, with more complete responses, prolonged time to recurrence and survival, than paclitaxel and docetaxel in MBC. As second-line treatment, the novel formulation has almost doubled overall response rate, increased time to progression and overall survival in comparison with paclitaxel. Due to these results, to date nab-paclitaxel stands out as a promising treatment of metastatic breast cancer.

Multicenter, phase II, nonrandomized study of docetaxel plus trastuzumab every 21 days as the primary therapy in metastatic breast cancer overexpressing HER2.

Different anthracycline-free regimens have demonstrated activity, without serious cardiac events. This study was conducted to evaluate the activity and toxicity of docetaxel and trastuzumab given every 21 days in patients with metastatic breast cancer (MBC). The primary endpoint was time to progression and the secondary aims included response rate, safety, duration of response, and overall survival. Eligible patients were those with MBC human epidermal growth factor receptor-2+ (HER2+) with no previous chemotherapy for advanced disease. Patients received six cycles of docetaxel (100 mg/m) plus trastuzumab (8 mg/kg loading dose and 6 mg/kg every 21 days thereafter), followed by maintenance treatment with trastuzumab monotherapy every 21 days until disease progression. Forty-nine patients with HER2+ MBC were included. The overall response rate was 44.9% (22/49). With a median follow-up of 16.6 months, the median time to progression was 8.3 months and the median overall survival was 25.7 months. Nineteen patients did not receive treatment continuation with trastuzumab monotherapy. The most common toxicity was febrile neutropenia. A total of 10 patients were taken off the study due to treatment-related toxicity, mainly cardiac events. First-line trastuzumab combined with docetaxel is an effective and well tolerated regimen for HER2+ MBC.

SEOM clinical guidelines for the treatment of metastatic breast cancer.

Patients with metastatic breast cancer have a wide number of treatment options, including medical, surgical, and supportive care measures. Treatment decisions are based in predictive and prognostic factors and the informed choice of the patients. SEOM has elaborated these guidelines with evidence-based recommendations for the diagnostic work-up, treatment (chemotherapy, endocrine therapy and targeted therapies) and supportive care for the management of these patients.

Supportive care for patients with early breast cancer.

Breast cancer treatment currently requires the joint efforts of a multidisciplinary team to effectively combine chemotherapy, hormone therapy, biological agents, surgery and radiation therapy when needed. To develop such a treatment plan, it is important to know the benefits as well as the potential toxic effects of each therapy. Thus, many patients with early breast cancer complain of collateral adverse events such as fatigue, nausea, vomiting, loss of libido, hot flashes, night sweats or neuropathy due to the complex therapies they are receiving. To date, the treatment of such symptoms is an important issue that greatly affects the quality of life of these patients. In this review, we report the content of a multi-expert meeting where the incidence of and medical approach to some of the most common adverse events encountered during the treatment of patients with early breast cancer were analysed.

Novel therapeutic approaches to the treatment of metastatic breast cancer.

Metastatic breast cancer is ultimately an incurable disease, although recent data have shown that its incidence is decreasing and that patients with metastatic breast cancer live longer. This improvement in survival seems to be linked with the introduction of new therapeutic agents, novel combinations of existing therapies and targeted therapies. Our increasing understanding of the molecular biology of metastatic disease has allowed the development of therapies aimed at specific molecular targets. Some of these have already been approved for the treatment of metastatic breast cancer in combination with cytotoxics, and others have shown promising results regarding disease-free survival, overall response rates and time to disease progression. Given the enormous amount of information about drug discovery in cancer, it is important to be familiar with the present state of the treatment of metastatic breast cancer. The purpose of this review is to provide an update on the development of some of the most promising novel agents and treatment strategies in metastatic breast cancer.